Method and apparatus for laser impulse sample deposition

ABSTRACT

A sample material, such as a liquid including genomic or proteomic materials, may be deposited on a work surface based on illumination of a sample transfer device by an illumination beam. Illumination of the sample transfer device may cause a portion of the sample transfer device to move and thereby cause separation of a portion of the sample material from the sample transfer device and deposition on a work surface. Illumination may cause an energy transfer from the beam to the sample material to thereby cause deposition of the sample material.

BACKGROUND OF INVENTION

1. Field of Invention

This invention relates to deposition of sample materials using a laseror other illumination beam.

2. Description of Related Art

Manipulation of material samples is important in a variety of fields,such as in automated proteomic, genomic, and other biotech-relatedresearch. Commonly, material samples are handled in liquid form using avariety of different types of liquid handling apparatus, such aspipettors, robotically-manipulated liquid handling tools, spottingdevices, etc. To improve processing times, sample density or otherfeatures, particularly in automated research operations, sample sizeshave been made progressively smaller and smaller. In some case, standardliquid handling apparatus, such as hand-held pipettors, are not suitablefor manipulating small sample volumes, such as nanoliter-sized samples.

SUMMARY OF INVENTION

In one aspect of the invention, a sample may be deposited on a worksurface based on an illumination beam being incident on a sampletransfer device. For example, a liquid material may be positioned on ornear a sample transfer device, and when the sample transfer device isilluminated by an illumination beam, at least a portion of the samplematerial may be transferred to a work surface. By controlling thedeposition of samples based on an illumination beam, the size and/orposition of the deposited sample on the work surface may be closelycontrolled.

In one aspect of the invention, a sample depositing system includes anillumination source that forms an illumination beam. For example, theillumination source may be or include a laser, such as a YAG laser. Asample transfer device may carry a sample material to be deposited on awork surface. The sample transfer device may include at least one layerof a material that is relatively transparent to the illumination beam,such as quartz, another inorganic material or other plastic material.The sample transfer device may also include a layer of opaque ortransmission-resistant material, such as a layer of nickel or aluminum,a plastic material such as mylar, or other material. Illumination of aportion of the sample transfer device by the illumination beam may causea portion of the sample material carried by the sample transfer deviceto be separated from the sample transfer device and deposited on a worksurface. The mechanism by which the portion of sample material isseparated from the sample transfer device may vary in different ways.For example, in one aspect of the invention, illumination of the sampletransfer device by the illumination beam may cause uneven heating and/orexpansion in portions of the sample transfer device. This unevenheating/expansion can cause the sample transfer device to buckle orotherwise move rapidly, releasing a portion of the sample carried by thesample transfer device. However, sample deposition does not result fromthe separation of a portion of the sample transfer device adjacent thesample material that carries sample material with it.

In another aspect of the invention, illumination of the sample transferdevice can cause localized heating of a portion of the sample transferdevice and/or the sample material. This localized heating may cause arapid expansion, e.g., caused by vaporization of a portion of the sampletransfer device and/or the sample material. This rapid expansion maycause a portion of the sample material to be separated from the sampletransfer device and deposited on a work surface.

In another aspect of the invention, illumination of the sample transferdevice and/or the sample material may transfer kinetic or other energyfrom the illumination beam to a portion of the sample material, causingthe portion of sample material to be separated from the sample transferdevice. For example, the illumination beam may cause bonds in the samplematerial and/or between the sample material and the sample transferdevice to be broken and release energy, thereby causing deposition of aportion of the sample material.

In one aspect of the invention, a sample depositing system includes anillumination source that forms an illumination beam, and a sampletransfer device that receives the illumination beam from theillumination source. A sample material may be carried by the sampletransfer device, and a controller may cause the illumination source toilluminate the sample transfer device and thereby cause at least aportion of the sample material carried by the sample transfer device tobe controllably separated from the transfer device and deposited on awork surface. The portion of sample material may be deposited withoutrequiring a portion of the sample transfer device positioned adjacentthe sample material to separate from the sample transfer device.

In another aspect of the invention, a method for depositing a samplematerial includes providing a sample material on a sample transferdevice, and illuminating the sample transfer device with an illuminationbeam. At least a portion of the sample material may be caused to beseparated from the sample transfer device and deposited on a worksurface in response to illumination of the illumination beam. Theportion of the sample material may be deposited without requiring aportion of the surface positioned adjacent the sample material toseparate from the sample transfer device.

These and other aspects of the invention will be apparent and/or obviousfrom the following detailed description and appended claims.

BRIEF DESCRIPTION OF DRAWINGS

Aspects of the invention are described in connection with the followingillustrative drawings in which like numerals reference like elements,and wherein:

FIG. 1 is a sample deposition apparatus in accordance with one aspect ofthe invention;

FIG. 2 shows a side view of a first embodiment of a sample transferdevice emitting a sample droplet;

FIG. 3 shows a side view of another illustrative embodiment of a sampletransfer device emitting a sample droplet;

FIG. 4 shows a side view of another illustrative embodiment of a sampletransfer device having a projection extending into a sample material;

FIG. 5 shows a side view of yet another embodiment of a sample transferdevice having a nozzle-like cavity;

FIG. 6 shows a side view of another illustrative embodiment of a sampletransfer device having an internal cavity from which a sample materialis expelled;

FIG. 7 shows a side view of another illustrative embodiment of a sampletransfer device having an internal cavity and a moveable driver member;

FIG. 8 illustrates a sample droplet being expelled from the FIG. 7embodiment;

FIG. 9 shows an illustrative embodiment including a mask that defines atleast one location where sample material is deposited on a work surface;and

FIG. 10 shows an illustrative embodiment of a sample transfer deviceincluding an explosive or other reactive substance.

DETAILED DESCRIPTION

This invention is not limited in its application to the details ofconstruction and the arrangement of components set forth in thefollowing description or illustrated in the drawings. The invention iscapable of other embodiments and of being practiced or of being carriedout in various ways. Also, the phraseology and terminology used hereinis for the purpose of description and should not be regarded aslimiting. The use of “including,” “comprising,” or “having,”“containing”, “involving”, and variations thereof herein, is meant toencompass the items listed thereafter and equivalents thereof as well asadditional items.

Aspects of the invention relate to controllably depositing a samplematerial on a work surface. In the illustrative embodiments describedbelow, the sample material includes a liquid and the sample material isdeposited in a droplet form. However, it should be understood that thesample material need not be or include a liquid, but instead may be orinclude a solid. Moreover, the sample material may include one elementor composition, or include a combination of two or more elements orcompositions. For example, the sample material may be a mixture of DNAor other genomic fragments in a liquid carrier material. In short, notall aspect of the invention are limited to depositing any particulartype of sample material.

FIG. 1 shows a sample depositing system in accordance with one aspect ofthe invention. In this illustrative embodiment, a sample transfer device1 cooperates with an illumination source 2, such as a laser, and acontroller 3 to controllably deposit at least a portion of a samplematerial 5 on a work surface 4. In this embodiment, the sample material5 is carried by the sample transfer device 1 on a surface nearest thework surface 4 although the sample material 5 may be positioned in anysuitable way relative to the sample transfer device 1 as will bediscussed in more detail below. The work surface 4 is shown as being aflat, planar surface, but the work surface 4 may have any suitable form,such as a microtiter plate or a similar device having multiple wells orother sample holders, an absorbent material, or other suitable device orregion to receive the sample material 5.

The sample transfer device and the way in which the sample material isassociated with the sample transfer device 1 operate to deposit at leasta portion of the sample material 5 on the work surface 4 upon suitableillumination from the illumination source 2. For example, illuminationof the sample transfer device 1 may cause a portion of the sampletransfer device 1 to move and thereby expel a droplet of the samplematerial 5. In another illustrative embodiment, illumination of thesample transfer device 1 can heat a portion of the sample transferdevice 1 and/or the sample material 5 which causes deposition of aportion of the sample material 5 to occur. For example, a portion of thesample material 5 may heat rapidly in response to the illumination,causing a vapor bubble to form and thereby cause a droplet of the samplematerial 5 to be expelled. In another illustrative embodiment,illumination of the sample transfer device can transfer kinetic or otherenergy from the illumination to a portion of the sample material 5 andcause separation of at least a portion of the sample material from thesample transfer device 1. For example, the sample material 5 may includea material that, when illuminated by the beam 2, has atomic or otherbonds that break and release energy to cause a portion of the samplematerial to be expelled. In another embodiment, adhesive or cohesivebonds between portions of the sample material 5 and/or the sampletransfer device 1 may be broken by illumination of the beam, causing aportion of the sample material to be separated and deposited. Whateverthe mechanism for deposition, however, illumination of the sampletransfer device 1 does not cause a portion of the sample transfer device1 on a side near the sample material 5 to break away and carry a portionof the sample material 5 with it.

The illumination provided by the illumination source 2 may be in anysuitable form, in some cases depending upon the mechanism by whichsample material is separated from the sample transfer device 1. Forexample, the illumination source 2 may be a laser, such as an YAG laserthat emits a beam toward the sample transfer device 1. The illuminationbeam may be focused, collimated or have any other suitable form.Moreover, the beam may be steerable so that the beam illuminatesselected portions of the sample transfer device 1. This may allow theillumination source 2 to address different portions of the sampletransfer device 1 and control the positions at which sample material 5is deposited on the work surface 4. For example, the sample transferdevice 1 may include several areas where a sample material 5 is carried.The illumination source 2 may selectively illuminate these separateportions of the sample transfer device 1 so that the sample material isdeposited into selected wells or other defined areas of the work surface4. Of course, the illumination source 2 need not include a laser, butmay provide any suitable visible or invisible electromagneticillumination. In addition, the illumination source 2 may provide two ormore beams that may be emitted simultaneously or sequentially, asdesired.

The controller 3 may include any suitable components for performingsample deposition functions. For example, the controller 3 may includeany suitable general purpose data processing system, which can be, orinclude, a suitably programmed general purpose computer or network ofcomputers and other associated devices including communication devices,and/or other circuitry or components necessary to control operation ofthe illumination source 2. In addition, the controller 3 may controldevices that move the sample transfer device 1 and/or the work surface4, e.g., where such movement is used to control the position wheresample material is deposited. Thus, the controller 3 may include roboticmanipulators or other drives to move the illumination source 2, thesample transfer device 1 and/or the work surface 4. The controller 3 mayalso include other devices, such as an information display device (aprinter, monitor or other device), user input devices (a keyboard, userpointing device, touch screen or other user interface), data storagedevices (magnetic, optical or other memories), or other suitabledevices.

FIG. 2 shows one illustrative embodiment of a sample transfer device 1having at least two layers 11 and 12 and a movable portion. A firstlayer 11 may include a first material such as a material that istransparent or translucent to the illumination beam from theillumination source 2. For example, the first layer 11 may include aquartz material, a plastic or other suitable material. A second layer 12may include a material that is opaque to or otherwise impedes passage ofthe illumination through the sample transfer device 1. In thisembodiment, the second layer 12 may include a metallic material, such asnickel or aluminum, a ceramic material, a liquid material, a gel, aplastic material or other suitable material. Upon illumination of thesample transfer device by an illumination beam, a portion of the sampletransfer device 1 may move, causing a droplet 51 to be formed from thesample material 5 and deposited on the work surface 4. However, duringmovement of a portion of the sample transfer device 1, no portion of thesample transfer device 1 breaks away on a side near the sample material5 to carry a portion of the sample material 5 (e.g., in a shrapnel-likeeffect) or otherwise cause deposition of the sample material 5. Instead,in this embodiment, the sample transfer device 1 stays generally intactwhile a portion of the device 1 moves to cause deposition.

FIG. 3 shows another illustrative embodiment and a mechanism by which asample transfer device 1 may operate to expel a droplet 51 from thesample material 5. This embodiment is different from the FIG. 2embodiment in that the second layer 12 of opaque ortransmission-resistant material has a first layer 11 a of a transparentor translucent material on a top side and a third layer 11 b of amaterial on a bottom side. The third layer 11 b may separate the secondlayer 12 from the sample material 5 (e.g., to prevent the second layer12 from contaminating or otherwise contact the sample material 5), andmay or may not operate with the first and second layers 11 a and 12 tocause deposition of a portion of sample material. However, theprinciples of operation of the FIG. 3 embodiment may apply to the FIG. 2embodiment.

Prior to illumination, the sample transfer device 1 may be slightlyconcave up or flat with the sample material carried by the device 1 on alower surface, as shown on the left in FIG. 3. Upon illumination, thesample transfer device 1 may move from the concave up or flat positionto a concave down or flat position, as shown on the right in FIG. 3.This movement may cause a droplet 51 to be formed from the samplematerial 5 whereupon the droplet 51 is deposited on the work surface 4.Movement of the sample transfer device 1 may be caused, for example, byuneven expansion rates of the first and second layers 11 a and 12 (orthe second and third layers 12 and 11 b, or the first, second and thirdlayers 11 a, 12, and 11 b) when heated by the illumination beam. Forexample, depending on the geometry of the sample transfer device 1, thefirst layer 11 a may expand more rapidly or more slowly than the secondlayer 12 in response to the illumination beam. This difference inexpansion rates may cause the sample transfer device 1 to rapidly moveor buckle causing the droplet 51 to be formed. However, the differentexpansion generally will not cause portions of the sample transferdevice 1 to break away or otherwise separate on a side near the samplematerial 5. Although heating may be caused directly by the illuminationbeam, heating may be caused indirectly, e.g., by the beam activating anoptically-controlled switch that allows current to flow through anelectrical resistance heater in or on the sample transfer device 1.

FIGS. 2 and 3 show that the sample transfer device 1 has anapproximately planar profile, but it should be understood that thesample transfer device 1 need not necessarily be made in a planar form.In addition, the sample transfer device 1 may have any suitable shape orconfiguration as viewed from the top, i.e., a direction parallel to thedirection in which the droplet 51 is expelled as shown in FIGS. 2 and 3.For example, the sample transfer device 1 may have a rectangular,circular or other shape. Moreover, the layers 11 and 12 and otheradditional layers need not be formed continuously across the entiresample transfer device 1. Instead, the layers may be formed in adiscontinuous or other suitable pattern. For example, the second layer12 including the metallic material may be provided in concentric annularrings, parallel strips, or other suitable patterns. In addition, thesample transfer device 1 need not move upward to expel a drop as shownin FIG. 3, but instead may move downward, sideways or in another fashionto expel a droplet 51. Likewise, the sample transfer device need notexpel drops only in a downward direction (with the force of gravity),but instead may deposit sample material in an upward or sidewaysdirection. For example, expelling a drop upward (against the force ofgravity on the drop) may allow for more control of the size, volumeand/or weight of drops deposited on the work surface. That is,excessively large drops may not have sufficient energy when expelled toovercome the force of gravity and reach the work surface. Thus, onlydrops of a certain size or smaller may be successfully deposited. Inaddition, expelling drops upwardly may allow for easier positioning ofsample material 5 on the sample transfer device, e.g., in someapplications liquid sample material 5 may not be easily positioned on abottom surface of a sample transfer device as shown in FIG. 1, andinstead may be easier placed on a top side of the sample transfer device1.

FIG. 4 shows another illustrative embodiment of a sample transfer device1 having at least one projection 13. The projection 13 may function tohelp in separating a portion of the sample material 5 from the sampletransfer device 1. For example, the projection 13 may serve a mechanicalfunction to help in forming a droplet 51, e.g., by forming adiscontinuity in the surface in the sample material 5 that helps to forma droplet 51. Alternately, the projection 13 may perform an opticalfunction, e.g., by focusing illumination from the illumination source 2to a particular portion of the sample transfer device 1 and/or thesample material 5. Focusing of the illumination may cause more rapidheating in selected locations and/or serve to more efficiently transferkinetic or other energy from the beam to portions of the sample material5. In another illustrative embodiment, the projection 13 may perform aheating function, e.g., where the projection 13 is arranged to berapidly heated by the illumination beam and to conduct its heat to thesample material 5. This heat transfer may in turn heat the samplematerial 5, forming a bubble that causes a droplet 51 to be expelled.The projection 13 may have any suitable shape, which may depend upon thefunction that it performs in the sample transfer device 1. Similarly,the sample transfer device 1 may have multiple layers of differentmaterial, e.g., as in FIG. 2 or 3, or have any other suitableconfiguration.

FIG. 5 shows another illustrative embodiment of a sample transfer device1 having at least one cavity 14. One or more cavities 14 in the sampletransfer device 1 may aid in the formation of droplets expelled from thesample transfer device 1. For example, a cavity 14 may serve to focus orotherwise direct pressure waves in a liquid sample material 5 when oneor more portions of the sample transfer device 1 moves, e.g., in a waylike that shown in FIG. 3. The focusing or other effect on pressurewaves may help form a droplet 51 when depositing a sample. Alternately,a cavity 14 may serve to preferentially heat one portion of the sampletransfer device 1 or the sample material 5. For example, the cavity 14may increase the surface area of the sample transfer device 1 in contactwith the sample material 5, thereby increasing the heat transfer andconsequent formation of a droplet 51 to be expelled. The cavity 14 mayhave any suitable size and/or shape depending on the function itperforms. Moreover, the sample transfer device 1 may have two or morecavities 14 that may be individually addressed by the illuminationsource 2 or may otherwise individually form droplets 51 that areexpelled from the sample transfer device 1. Like the projections 13 inFIG. 4, one or more cavities 14 may be incorporated in any type ofsample transfer device, including those having two or more layers.Moreover, projections 13 and cavities 14 may be combined into singledevice and work together to deposit sample material 5.

FIG. 6 shows another illustrative embodiment of a sample transfer device1 having an internal chamber 16 and an opening 15. In this illustrativeembodiment, a sample material 5 is located in the chamber 16. The samplematerial 5 may or may not entirely fill the chamber 16. Uponillumination of the sample transfer device I, at least a portion of thesample material 5 may be expelled through the opening 15 and depositedon a work surface 4. The cause of the sample material 5 being forcedthrough the opening 15 may be any of those described above, namely aheating of the sample material 5 or gas or other material in the chamber16, movement of one or more portions of the sample transfer device I, ora transfer of kinetic or other energy from the illumination beam toportions of the sample material 5. For example, FIG. 7 shows oneillustrative embodiment in which an upper portion of the sample transferdevice 1 includes first and second layers 11 and 12 like that in theFIG. 2 embodiment. As can be seen in FIG. 8, illumination of the sampletransfer device 1 may cause the first and second layers 11 and 12 tomove from a rest position to a deflected position, e.g., a concave upcondition shown in FIG. 8, which forces sample material in the chamber16 through the opening 15. As with other illustrative embodiments, thesample transfer device may include multiple chambers 16 with multipleopenings 15 from which droplets 51 may be expelled. Alternately, thesample transfer device 1 may be provided with one relatively largechamber 16 that communicates with two or more openings 15 through whichdroplets are expelled.

In another illustrative embodiment shown in FIG. 9, a mask 16 may beprovided with a pattern of openings 15 and the sample transfer device 1may expel sample material 5 in the general direction of the mask. Themask 16 may then selectively block portions of the sample materialexpelled by the sample transfer device 1, only allowing sample materialto be deposited through the openings 15 in the mask 16 and onto desiredlocations on the work surface 4. The mask 16 may be secured to thesample transfer device 1, or may be separate.

In another illustrative embodiment shown in FIG. 10, the sample transferdevice 1 may have an explosive or other reactive substance or substances17 on a portion of the sample transfer device 1. This substance 17 mayexplode or expand rapidly upon illumination of the illumination beam,thereby transferring kinetic energy to the sample transfer device 1. Theexplosion or rapid expansion may cause a portion of the sample transferdevice 1 to move and cause a deposition of the sample material 5. Thesubstance 17 may be provided in discrete locations on the sampletransfer device 1 and selectively illuminated, the substance may beprovided in a continuous layer and selectively illuminated, or other.

Various aspects of the invention may be particularly useful indepositing liquid samples of genomic, proteomic or other materials usedin biotech research. Extremely small volume droplets may be producedusing various aspects of the invention, with droplet volumes rangingdown to the nanoliter size range. Aspects of the invention also allowsample deposition to occur with few moving parts and limited contactbetween the sample and the deposition apparatus.

While the invention has been described with reference to variousillustrative embodiments, the invention is not limited to theembodiments described. It is evident that many alternatives,modifications and variations of the embodiments described will beapparent to those skilled in the art. Accordingly, embodiments of theinvention as set forth herein are intended to be illustrative, notlimiting. Various changes may be made without departing from theinvention.

1. A sample depositing system comprising: an illumination source thatforms an illumination beam; a sample transfer device that receives theillumination beam from the illumination source, the sample transferdevice including a portion constructed and arranged to move in responseto suitable illumination incident on the sample transfer device; asample material carried by the sample transfer device; and a controllerthat causes the illumination source to illuminate the sample transferdevice and thereby cause the portion of the sample transfer device tomove, movement of the portion of the sample transfer device causing atleast a portion of the sample material carried by the sample transferdevice to be controllably separated from the transfer device anddeposited on a work surface, the portion of sample material beingdeposited without any part of the sample transfer device positionedadjacent the sample material separating from the sample transfer device.2. The system of claim 1, wherein the sample transfer device includes:at least one layer of a material that is translucent or transparent tothe illumination beam; and at least one layer of a material that isopaque to or substantially impedes transmission of the illuminationbeam.
 3. The system of claim 1, wherein the sample transfer deviceincludes: at least one layer of a transparent material that istransparent to the illumination beam; and p1 at least one layer of anopaque material that is opaque to the illumination beam.
 4. The systemof claim 3, wherein the layer of transparent material and the layer ofopaque material are positioned adjacent to each other and the adjacentlayers are constructed and arranged to move in response to illuminationfrom the illumination beam.
 5. The system of claim 3, wherein the atleast one layer of opaque material is separated from the sample materialby a plastic material.
 6. The system of claim 3, wherein the opaquematerial includes one of a plastic, a metal, a ceramic, a liquidmaterial and a gel.
 7. The system of claim 3, wherein the at least onelayer of opaque material is surrounded by a plastic material.
 8. Thesystem of claim 1, wherein the sample material includes a liquidmaterial.
 9. The system of claim 1, wherein the sample material iscarried by the sample transfer device on a side of the sample transferdevice opposite the illumination source.
 10. The system of claim 1,wherein the sample transfer device includes a metal layer surrounded bya clear plastic material.
 11. The system of claim 1, wherein the portionof sample material is separated from the sample transfer device indroplet form.
 12. The system of claim 1, wherein the illumination sourceincludes a laser.
 13. The system of claim 1, wherein the sample transferdevice includes a chamber that communicates with an opening, and atleast a portion of the sample material is located in the chamber. 14.The system of claim 1, wherein the sample transfer device includes atleast one of a projection and a cavity constructed and arranged to aidin formation of a droplet of sample material.
 15. The system of claim 1,further comprising a mask having at least one opening, the at least oneopening defining a location in which sample material is deposited on awork surface.
 16. The system of claim 1, wherein the sample transferdevice includes a substance that explodes or expands rapidly uponillumination by the illumination beam and causes the portion of thesample transfer device to move.
 17. The system of claim 1, wherein theportion of sample material being deposited moves in a directiongenerally against a force of earth's gravity and away from the sampletransfer device.
 18. A method for depositing a sample material,comprising: providing a sample material on a sample transfer device, thesample transfer device having a portion that moves in response tosuitable illumination incident on the sample transfer device;illuminating the sample transfer device with an illumination beam;causing the portion of the sample transfer device to move so that atleast a portion of the sample material is separated from the sampletransfer device and deposited on a work surface in response toillumination of the illumination beam, the portion of the samplematerial being deposited without any portion of a surface positionedadjacent the sample material separating from the sample transfer device.19. The method of claim 18, wherein the step of causing includes movingat least a portion of the surface in response to illumination of theillumination beam.
 20. The method of claim 18, wherein the step ofcausing includes transferring energy from the illumination beam to thesample material.
 21. The method of claim 18, wherein the step of causingincludes heating a portion of the sample material by the illuminationbeam.
 22. The method of claim 18, wherein the step of providing a samplematerial on a surface includes providing the sample material in achamber that communicates with an opening, and the step of causingincludes causing a portion of the chamber to move in response toillumination by the illumination beam and expelling a portion of thesample material through the opening.
 23. The method of claim 18, furthercomprising providing a mask having at least one opening, the at leastone opening defining a location in which sample material is deposited ona work surface, and the step of causing includes expelling a portion ofthe sample material in a direction toward the mask.
 24. The method ofclaim 18, wherein the step of providing a sample material includesproviding a sample transfer device having at least one layer of amaterial that is optically translucent or transparent to theillumination beam, and at least one layer of a material that is opaqueto or substantially impedes transmission of the illumination beam. 25.The method of claim 24, wherein the step of providing a sample materialincludes providing a sample transfer device having at least one layer ofa transparent material that is transparent to the illumination beam, andat least one layer of an opaque material that is opaque to theillumination beam.
 26. The method of claim 25, wherein the step ofcausing includes moving the adjacent layers in response to illuminationfrom the illumination beam.
 27. The method of claim 25, wherein the stepof providing a sample material includes providing a liquid samplematerial on a surface of the sample transfer device.
 28. A sampledepositing a system comprising: a sample transfer means for carrying asample material, the sample transfer means including a portion thatmoves in response to suitable illumination incident on the sampletransfer means; means for illuminating the means for carrying with anillumination beam; and means for causing the portion of the sampletransfer device to move so that at least a portion of the samplematerial is separated from the sample transfer means and deposited on awork surface in response to illumination of the illumination beam, theportion of the sample material being deposited without any part of thesample transfer means positioned adjacent the sample material separatingfrom the sample transfer means.